1. Field of the Invention
The present invention relates to a sheet conveyance device that feeds a recording sheet stacked in a sheet tray and more particularly to a sheet conveyance device in which a feed roll for feeding a recording sheet is movable between a feeding position and a feed standby position.
2. Description of the Related Art
An image forming apparatus such as a facsimile, a printer, and a copier has a sheet conveyance device such as a document feeder or a manual feeder for conveying a recording sheet. It has been known that the sheet conveyance device includes a pick-up roller for feeding the recording sheets, a feed roll, which is disposed on downstream of the pick-up roller in the sheet conveyance direction and conveys the recording sheet fed by the pick-up roller downstream, and a retard roll for separating the recording sheets one by one by pressing the recording sheets along with the feed roll.
When the recording sheets are separated one by one between the feed roll and the retard roll, the separated recording sheet may be dragged by a recording sheet to be carried downstream and may be conveyed again between the feed roll and the retard roll (a handling region). When the separated recording sheet is conveyed repeatedly to the handling region, noises (handling abnormal noises) may be caused. Particularly, in case of recording sheets having a low frictional coefficient between the recording sheets such as OHP sheets not closely contacting with each other or in case of recording sheets having a small size and a small weight such as postcards, the recording sheets can be easily moved. Accordingly, the handling abnormal noises may be easily caused.
As a technique for preventing the movement of the separated recording sheets, there has been known the following technique.
A pressing roller is disposed on upstream of a pick-up roller (call-out roller) in a sheet conveyance direction. Even after the pick-up roller is separated from a recording sheet, the movement of the separated recording sheets is prevented by pressing the upper surface of the recording sheet with the pressing roller. By using this technique, it is possible to prevent a recording sheet separated and dragged by the uppermost recording sheet from being conveyed again to the handling region.